1450mm Foam Corsair EP to Glow Conversion

[epanzella]

I have an AIRFIELD 1450mm Corsair that has never flown worth a damn. It never had enough power even after changing out the motor to the most powerful 4 cell I could find. I had no interest in going 6 cell. Being as I had a bunch of glow 60's laying around I decided to try to put one in this all foam plane. The biggest problem that I see is solidly grafting the 60's power and vibration to the foam fuse and making room for the fuel tank and throttle servo. This plane barely had room for the existing stuff before the conversion. I'm also concered about the additional weight and the fact that the design of the fuse prevents me from setting the engine back as far as I would like. This is going to cause some CG problems down the road but, hey, my other choice is to retire the plane so "BONSAI". First I cleaned up the exhaust port of the ENYA 61 on the mill to minimize oil leakage onto the foam plane. Then I made a custom exhaust which I covered in another thread. The foam nose was hogged out and a plywood box was epoxied in to tie the new firewall to the foam. A stop was put in to locate the 12 oz fuel tank and it was secured with closed cell foam. That's it for now. Will post more as the job progresses.

 

[pontiac428]

Did you have no interest in 6s because of the upgrade cost? I have a 6s 750mm warbird, and I'm afraid to blink, think, or sneeze at the sticks, lest I lose the rapidly shrinking dot in the sky. Of course, I'm sure the .61 will fly very nicely. How much weight change do you expect to see between electric and glow, all up?

 

[epanzella]

Did you have no interest in 6s because of the upgrade cost? I have a 6s 750mm warbird, and I'm afraid to blink, think, or sneeze at the sticks, lest I lose the rapidly shrinking dot in the sky. Of course, I'm sure the .61 will fly very nicely. How much weight change do you expect to see between electric and glow, all up?

The expense of 6S just turned me off in light of the fact that I have a ton of 3S, 4S, and glow stuff in my inventory. I just couldn't see adding something completely new for one plane. As fas as extra weight, I just don't know. The E-motor was a 46 size and the batt a 4S 5000mah so they weighed a bit. A concern is the CG as the 61 should be further aft but the construction of the foam fuse made that impossible. The tail moment being much longer than the nose moment means that a small weight in the tail will move the CG as much as a bigger weight in the nose. This plane had about 4 ounces in the nose from the factory. I tried to get some opinions on my RC groups but all I got was guys telling me to go 6S or I was an ice hole. They're probably right but I've always been an "out-of-the-box" kink of guy, often with less than stellar results. If I can get away an once or two in the tail I'll be a happy camper. I'll let you know what happens.

 

[pontiac428]

If you have 3s batteries, then you also have 6s capability. 2x 3s in series is 6s. Last year I set up 3x 2s =6s for a little balsa bird that I am afraid to fly based on MikeRx's planes here:
https://www.rcgroups.com/forums/sho...rk-build-experiment-UPDATE-250-GRAM-RACER-8S!

Anyway, that's a moot point now, you're committed. Hopefully you'll get 'er balanced nicely and enjoy the flight.

 

[Dhal22]

Good to see some progress. I'm hoping this endeavor goes well.

 

[epanzella]

If you have 3s batteries, then you also have 6s capability. 2x 3s in series is 6s. Last year I set up 3x 2s =6s for a little balsa bird that I am afraid to fly based on MikeRx's planes here:
https://www.rcgroups.com/forums/showthread.php?2921396-Minishark-Twinshark-build-experiment-UPDATE-250-GRAM-RACER-8S!

My 3s batts are only 1000mah for my YAK 54 3D plane. A 6s series connection would still only be 1000mah. That YAK is what turned me on to the smaller electrics. It's got a 43 inch wingspan and a profile fuse so it's lite. I fly 3 1/2 minutes on 1000mah 3s batts and the plane is a rocket. Hit the throttle and it flies straight up right out of my hand. No LG so it's good for small areas. Got some more done on the Corsair this PM. I'll post tomorrow. I'm jumping back and forth between making a tool for my boat and finishing the F4U. If this virus doesn't kill me it will allow me to work thru most of my backlogged projects!

 

[epanzella]

Finished the Corsair up yesterday. Made a pressure fitting out of an 8-32 brass bolt, epoxied in the firewall and mounted the motor. My CG concerns were justified as it took 4 ounces of lead in the tail to balance it on my home made balancing rig. I added a wire loom to keep the rudder and elevator servos from getting fouled because with the flaps, ailerons and retracts there's 6 servo leads coming out of the wing right there. Now I wait for spring while I tackle my next C19 project.